Cantilever sprinkler head for dry powder



Nov. 28, 1961 E- E. SEABERG CANTILEVER SPRINKLER HEAD FOR DRY POWDER Filed May 3, 1960 v 22 f I 5:5 23

mmvrox. ERNEST E. SEABERG AZ'IOZ/VEY United States Patent 3,010,521 CANTILEVER SPRINKLER HEAD FOR DRY POWDER Ernest E. Seaberg, Elmsiord, N.Y., assignor to Safety First Products Corporation, Elmsford, N.Y. Filed May 3, 1960, Ser. No. 26,454 2 Claims. (Cl. 169-40) This invention relates to a sprinkler head for dispensing dry powder fire extinguishing chemicals and more particularly to such a sprinkler head having a pair of opposed cantilever arms.

It is an objective of this invention to provide a sprinkler head for dispensing dry powder having a pair of opposed arms for retaining a piston in said head in an inoperative position.

It is another objective to provide a springler head having a 'heat sensitive low melting point retaining bar for maintaining a pair of cantilevered arms in a captively held position.

It is another objective to provide a reuseable sprinkler head for dry powder fire extinguishing chemicals having heat meltable easily replaced retaining means.

v These and other objects of this invention will become apparent upon reading the following descriptive disclosure taken in conjunction with the accompanying drawing in which:

FIG. 1 is a side elevation view of the sprinkler head,

FIG. 2 is a front section view of the sprinkler head showing the manner of captively maintaining a moveable piston in an air tight manner within the borehole of the body portion of said head,

FIG. 3 is a front section view of the sprinkler head of FIG. 2 showing the extended position of the piston in its dispensing position after the arms retaining the meltable retaining bar has melted, and

FIG. 4 is a bottom view of the sprinkler head.

Turning to the drawing, an integral body member 10 is provided with a tubular passageway terminating in a funnel shaped outlet 12. The body member 10 is made of metal and is provided with a polygonal portion 13 for engagement with a wrench, and also with a threaded tubular portion 14 for air tight engagement with a threaded coupling nut 15 secured to a conventional high pressure conduit (not shown) containing the dry powder fire extinguishing chemical under a high pressure of about 400 pounds per square inch.

The nozzle portion 16 of the body portion, contains the interiorly disposed funnel shaped cavity 12. The exterior surface of the nozzle portion 16 is provided with a suitable annular groove 17, in which a rigid U-shaped retaining pin 18 is disposed.

The nozzle portion 16 is provided with a pair of opposed slots 19 in planar relationship with each other.

A pair of cantilever arms 20 are each provided with a bevel edge 21 and with a suitably disposed aperture adjacent thereto through which pin 18 passes.

The bottoms of the arms 20 are each provided with an integral ledge portion 22 disposed at a right angle to the arm 20 and a suitable screw threaded aperture is disposed in each ledge 22. A suitable low melting point retaining bar 23 having suitable apertures is secured to the opposed pair of arms 20 by screw threads 24 (FIG. 4).

As shown in FIG. 2, the passageway of the body member 10 consists of a pair of merging boreholes, namely a top large diameter borehole 30 merging with a bottom smaller diameter borehole 31 (FIG. 2) so that an annular ledge 33 is formed in said passageway.

An integral movable cylindrical piston 35 is provided with a collar portion 36 having substantially the diameter of borehole 30 and also with a trunk portion 37 having substantially the diameter of the borehole 31.

The piston 35 is provided with a central cavity 38 leading to a plurality of radially disposed communicating port holes 39. The exterior wall of the trunk portion 37 of the piston 35 is provided with a suitably disposed annular groove and an O-ring 39 of resilient rubber or plastic material is captively disposed therein.

As shown in FIG. 2, the piston 35 is normally held in a captive position within the passageway of the body member 10. The pressure of the gas in the passageway causes the piston 35 to press against the bevel edges 21 of the respective cantilever arms 20, tending to force the arms 20 to pivot on the pin 18. However the heat meltable retaining bar 23 prevents such pivoting of the arms so that the piston is retained in the passageway of the body member 10 in an air tight manner due to the gas retaining O-ring 39.

When a fire starts under the depending sprinkler head (FIG. 2), the heat of the tire melts the meltable retaining bar 23 so that the force of the nitrogen gas in the passageway of the body member 10 pushes out the piston 35 until the collar 36 engages the ledge 33. In this position (FIG. 3) the ports 39 are disposed in the center of the funnel cavity 12 so that the high pressure nitrogen gas with its dry powder fire extinguishing chemical, mixed therein by conventional means, for example sodium bicarbonate, impinges on the funnel wall and thence as a cloud on the fire therebeneath.

After the fire is extinguished, the sprinkler head is easily made operable again by merely pushing in the piston 35 and pulling the arms 20 together, and replacing the remains of the old melted retaining bar 23 with a new retaining bar 23.

This invention has been described by means of an illustrative embodiment but it is not to be restricted to its illustration but only to the claims herein.

I claim:

1. A sprinkler head for dispensing dry powder fire extinguishing chemicals comprising an integral housing having a vertically disposed central cylindrical borehole therethrough having an interior ledge adjacent its base, said housing having a depending conical opening communicating With the base of said borehole and in suitable space relationship to said interior ledge, said housing being provided with a pair of spaced-apart diametrically opposed slots each extending through the housing wall forming the conical opening, said housing having an exterior circular groove disposed in the cone forming housing wall; cylindrical piston means disposed slidably in said borehole and having an interior cavity communicating with a plurality of lateral openings adjacent the front end thereof, said piston having an integral exteriorly disposed ledge adapted to arrestingly engage said interior ledge of said housing, said piston having an annular groove disposed in the cylindrical surface adjacent the front end; an O-ring of sealing resilient plastic material disposed in said annular piston groove and in gas tight relationship to said borehole; a pair of longitudinal arms having cam edges adjacent one end, each provided with an aperture in suitable space relationship to said cam edges, said cam edgm being disposed in said slots of said housing and adapted to engage the front wall of said piston in said borehole; a retaining pin disposed captively in said exterior groove of said housing and through said apertures of said arms and fusible means securing the ends 'of the arms awayfrom the cam edges in suitable V spaced-apart relationship with the piston disposed in said borehole.

2. The sp-rinkler head of claim 1 provided with a tubular nipple integral with said housing, disposed away from 5 References Cited in the file of this patent UNITED STATES PATENTS Brown May 22, 1883 Boardman Sept. 24, 1907 McErland Feb. 3, 1931 Zabriskie Aug. 21, 1956 FOREIGN PATENTS France Nov. 10, 1887 

